Stents and stent delivery assemblies are utilized in a number of medical procedures and situations, and as such their structure and function are well known. A stent is a generally cylindrical prosthesis that is introduced via a catheter into a body lumen or cavity. The stent is introduced into the body lumen or cavity in a generally reduced diameter (i.e., collapsed) configuration and then expanded to an expanded configuration. In its expanded configuration, the stent supports and reinforces the body lumen or cavity while maintaining the body lumen or cavity in an open, unobstructed condition.
Various medical procedures require placement of large diameter stents within a body lumen or cavity. For example, certain endoscopic procedures may require the use of relatively large diameter stents for placement in the esophagus. Often, a stent is delivered to a target site via a stent delivery system. Some stent delivery systems position the stent between and exterior sheath and an inner support member for delivery to a target site. Loading a stent into this type of stent delivery system often involves sliding an exterior sheath overtop the stent and inner member. With larger stents, this process may result in increased friction forces between the stent and the exterior sheath. Therefore, in some instances it may be desirable to load a stent into a stent delivery system by collapsing a collapsible frame over the stent rather than sliding an exterior sheath overtop. Examples described herein disclose a stent delivery system designed to load a stent by radially collapsing the stent via a collapsible frame, without exposing the stent to longitudinally sliding or shear forces.